Sheila Dumesh
M.Sc. candidate
Honours B.Sc. in Biology, York University
e-mail: sdumesh@yorku.ca
Research Interests:
Sheila is one of the taxonomists in the Packer lab. For her MSc thesis she is working on a revision of the Mesoamerican bee genus Mexalictus. Sheila is also involved in some projects with other lab members such as the revision of Canadian Dufourea (with Cory Sheffield) and the bees of Algonquin Park (with Sheila Colla).
Mexalictus is a very rare genus of bees found at high elevations of the humid mountains ranges from Arizona south to Panama. These bees belong to the family Halictidae and are usually metallic in colour. The main distinguishing characteristics of the genus are strong distal wing venation and microserrated hind tibial spurs. Social and floral relations of this group are not well known. Field work is necessary in order to obtain more specimens from Mexico and Central America since the collection is limited to only one or two specimens for some species, and many species are only known from one sex.
Sheila is working on a revision of the bee genus, Mexalictus, which includes 5 described species and at least 10 undescribed. This project involves taxonomic descriptions of all species discovered to date, including known and new species. As a basis for differentiating species, she is selecting a number of morphological characteristics, each of which will be assigned several character states, which will be used to code each species. She will then input this information (character states) into a character matrix, comprising of all species of the ingroup (Mexalictus) and outgroups (Patellapis, Thrinohalictus). 
Sheila will perform phylogenetic analyses on the derived matrices, using tree generating programs, namely Winclada and TNT, which will result in a number of most equally parsimonious trees (MEPTs). A consensus tree will be generated by compiling all resulting MEPTs, which she will use to represent the lineage. In order to determine the significance of the suggested groupings, she will perform statistical analyses to obtain group support values. Lastly, Sheila will design a dichotomous key for the genus Mexalictus, which will allow others to identify species of this rare group of Mesoamerican bees.
Favourite Recipe:
Chocolate
(not really a recipe, but still)
Funniest Research Story:
Mmmmmm ... chilies ...
I was on a collecting trip in Chiapas, Mexico. We were walking along in the forest when I spotted a bush of these small berry-like chilies. I had just tasted them a few days earlier and they were great - I was so excited to pick some for myself! I started picking some and putting them into an empty vial. Later that week, I found another bush on the roadside FILLED with ripe red chilies. I asked my field assistant to pull over so that I could go pick some quickly. I was picking and picking, getting so excited at how many there were, when all of a sudden I look down on my hand to see it covered by about five or six 2" wasps stinging away. I swung my hand to try to get them off and ran onto the street and back to the car yelling. It was extremely painful, my hand was entirely swollen within a few minutes. Then I found out that those wasps were referred to as "choking wasps" by the locals because most people that get stung begin to choke. Thankfully I did not feel any side effects other than the pain up my entire arm. There was a wasp nest in the bush which I didn't see since it was at the level of my feet. I guess me shaking the bush while picking the berries didn't make these territorial wasps happy! It was just ironic how I got stung while I wasn't collecting bees... By wasps!